1. Technical Field
The present invention relates to an industrial robot, more specifically, a horizontal arm type multiarticulated robot equipped with an articulated horizontal arm assembly and, more particularly, to an improved direct teaching method and apparatus for carrying out the same which enable an operator to easily and simply carry out a teaching operation when directly teaching robot motions, with respect to a vertical axis, to a horizontal arm type multi-articulated robot having an end effector for executing programmed robot actions, such as a hand or a gripper, attached to the lower end of a motor-driven vertically movable shaft joined to the extremity of a horizontal arm assembly.
2. Background Art
The desired robotic motions of the movable units of an industrial robot, such as a wrist, an arm and a swivel body, meeting the application of the industrial robot are taught beforehand to the industrial robot, and a control program for controlling the desired robotic motions is stored in a robot control unit by teaching. Generally, the operator of the robot is required to directly carry out the teaching, and when carrying out this direct teaching, the drive sources for the movable units of the robot, namely, the motors, are made inoperative. Namely, the motors are disconnected from the power source. Concretely, when teaching each movable unit, the operator manually operates the movable unit in an optimum sequence of motions to store positions and operating paths to be stored in the robot control unit. Accordingly, when teaching motions and positions of the vertically movable shaft to the horizontal arm type multi-articulated robot for carrying a workpiece, having an end effector, such as a hand or a gripper, attached to the lower end of the vertically movable shaft joined to the extremity of the horizontal arm assembly, the drive motor for driving the vertically movable shaft is made inoperative and the operator must move the vertically movable shaft, bearing the respective weights of the vertically movable shaft, the end effector, and a workpiece.
Consequently, the activity of the operator is hindered and the teaching of the desired motions and positions is difficult, and thus it is impossible to readily and simply carry out the objective teaching, because the bearing of the weight is a heavy load on the operator when teaching the horizontal arm type multiarticulated robot. No measures for directly solving such problems have been proposed.